Fluted roll slip drafting system

ABSTRACT

Apparatus for drafting fibrous textile material in which a drafting system includes at least one three-roll control unit having first and second intermeshing fluted feed rolls and a fluted slip roll adjacent on of the feed rolls and spaced forwardly of the nip of the feed rolls. A first one of the feed rolls is driven positively from a power source to, in turn, rotate the other feed roll solely by the intermeshing relationship of the feed rolls and the textile material passing therebetween whereby the textile material is gripped between and fed by the feed rolls. The slip roll is driven in fixed angular relation to one of the feed rolls, but not to the other, to cause the teeth of the slip roll to register with the grooves between the teeth of said first one of the feed rolls, without gripping the textile material passing therebetween, and thereby to cause the material therebetween to move in an undulating path while a fiber-distributing slip draft thus is applied to the material as it is being pulled therebetween and drafted in its forward course from the nip of the feed rolls.

United States Patent Whitehurst FLUTED ROLL SLIP DRAFT ING SYSTEM [72] Inventor: Joe R. Whitehurst, Bessemer City,

[73] Assignee: The Warner 8r Swasey Company,

Cleveland, Ohio [22] Filed: Jan. 22, 1970 [21] Appl. No.: 4,868

[52] US. Cl ..l9/259 [51] Int. Cl. ..DOIh 5/78 [58] Field of Search 19/259, 260, 261, 251

[56] References Cited UNITED STATES PATENTS 505,887 10/1893 Richards 19/260 2,607,083 8/1952 Bird 19/251 3,304,584 2/1967 West et a1 19/261 3,371,389 3/1968 Whitehurst 19/259 3,479,700 11/1969 Livingston l 9/260 FOREIGN PATENTS OR APPLICATIONS 407,707 3/1934 Great Britain l9/259 407,706 3/1934 Great Britain 19/259 I451 Oct. 3, 1972 Primary Examiner-Dorsey Newton Attorney-Parrott, Bell, Seltzer, Park & Gibson ABSTRACT Apparatus for drafting fibrous textile material in which a drafting system includes at least one three-roll control unit having first and second intermeshing fluted feed rolls and a fluted slip roll adjacent on of the feed rolls and spaced forwardly of the nip of the feed rolls. A first one of the feed rolls is driven positively from a power source to, in turn, rotate the other feed roll solely by the intermeshing relationship of the feed rolls and the textile material passing therebetween whereby the textile material is gripped between and fed by the feed rolls. The slip roll is driven in fixed angular relation to one of the feed rolls, but not to the other, to cause the teeth of the slip roll to register with the grooves between the teeth of said first one of the feed rolls, without gripping the textile material passing therebetween, and thereby to cause the material therebetween to move in an undulating path while a fiber-distributing slip draft thus is applied to the material as it is being pulled therebetween and drafted in its forward course from the nip of the feed rolls.

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ATTORNEYS PATENTEDucI 3 m2 SHEEI 5 1F 5 ATTORNFYS FLUTED ROLL SLIP DRAFTING SYSTEM SUMMARY OF THE INVENTION The art involving three-roll units for controlling fibrous textile material during drafting thereof has become highly developed during the past century. some early representative developments being disclosed in British Pat. Nos. 9,254 of I842 (Jarmon); 4,922 of I877 (McPherson); and 10,424 of I893 (Mackie et al.), for example. For more recent disclosures of three-roll fiber-controlling units, reference is made, for example, to the following United States Pat. Nos: Spencer 2,624,919, dated .Ian. 12, I953; Bisinger et al. 2,715,754, dated Aug. 23, 1955; West et al. 3,304,584, dated Feb. 2], 1967; and Whitehurst 3,37 l ,389, dated Mar. 5, I968.

The patents mentioned above disclose three-roll units in various combinations of smooth and/or fluted rolls, and certain of the three-roll units are designed to apply slip draft to the textile material passing therethrough. While certain of the prior art three-roll units have advanced the art of slip drafting considerably and have substantially improved the uniformity of textile material, it has now been discovered that the uniformity of textile material, especially heavy material of up to 600 grains/yd. and more, may be further improved by a novel arrangement of three fluted rolls and a novel manner of driving the same. I It is therefore an object of this invention to provide a textile drafting system which includes at least one three-roll control unit comprising first and second intermeshing fluted feed rolls arranged to firmly grip or pinch the textile material therebetween, and a fluted slip roll spaced forwardly from the nip of the feed rolls and out of contact with the first feed roll, but positioned with respect to the first feed roll so as to define a restricting undulating passage therebetween to impart an undulating configuration to the textile material and apply slip draft thereto as it is being pulled and thereby drafted from the nip of the feed rolls through the restricting undulating passage to a point forwardly of the three rolls.

It is another object of this invention to provide apparatus for imparting draft to fibrous textile material while improving the uniformity thereof, wherein the textile material is fed through a drafting zone while a retardant fiber-distributing slip draft force is being applied to the textile material. Such slip draft force is applied by directing the material being fed through a restricting passage of undulating configuration defined between proximal spaced apart fluted rolls rotating at the same peripheral speed to avoid scuffing the textile material while imparting an undulating configuration thereto. The peripheral speed of the fluted rolls is less than the rate of feed of the textile material, and the rate of feed is less than the rate at which the material is being pulled forwardly between the fluted rolls to thereby obtain improved distribution of the fibers to enhance the uniformity of the textile material. By utilizing spaced apart, rotating, fluted rolls as described, the textile material is subjected to successive opposing impacts by the flutes to aid in opening the fibers while a slip draft force is being applied to the textile material, thereby multiplying the effectiveness of the slip draft being applied in controlling the fibers as compared to known prior art systems of slip drafting. Neps in the textile material are practically eliminated.

Two embodiments of the improved drafting system and associated three-roll control units are disclosed herein. In each embodiment of the three-roll control unit, all three fluted rolls are of the same circular pitch, the first and second feed rolls are in relatively deep intermeshing relationship, and the second feed roll and the slip roll either may be in relatively shallow intermeshing relationship or entirely out of intermeshing relationship, as desired. In either event, in order that the second feed roll and the slip roll will impart the desired slip draft to the textile material in accordance with this invention, it is necessary that a predetermined angular or rotational relationship be maintained between the second feed roll and the slip roll at all times during drafting of the textile material. More specifically, at the nip of the second feed roll and the slip roll, the land and opposing side surfaces of each successive tooth of the second feed roll always must be positioned in a radial plane spaced from and between the lands and adjacent side surfaces of the corresponding adjacent pair of teeth of the slip roll so as to avoid tightly pinching and unduly restraining the textile material therebetween while imparting an undulating configuration to the textile material.

In the first embodiment, the aforementioned rotational relationship between the second feed roll and the slip roll is achieved by drive means interconnecting the first feed roll and the slip roll to impart positive rotation thereto and to, in turn, impart rotation to the second feed roll solely through its intermeshing relation with the first feed roll and the textile material passing therebetween. It should be noted that the leading side surface of each successive tooth of the positively driven first feed roll, at the nip of the feed rolls, is more closely adjacent the trailing surface of each successive tooth of the second feed roll than are the leading and trailing surfaces of adjacent teeth of the respective second feed roll and the slip roll, even though variations in the thickness and/or density of the textile material effect variations in the relative rotational angular positions of the feed rolls. This condition is effected because of the teeth of the second feed roll being disposed in substantially closer relation to the roots or bottoms of the grooves of the first feed roll than they are with respect to the roots or bottoms of the grooves of the slip roll at the nips thereof. Also, at the time of setting up the three-roll control unit, the second feed roll is positioned so that each successive tooth thereof will be located in a radial plane about midway between an ad jacent pair of teeth on the slip roll, at the nip thereof, while a portion of textile material of the desired optimum density, thickness and weight per unit length is being pinched between the leading and trailing surfaces of adjacent intermeshing flutes of the respective first and second feed rolls.

in the second embodiment, the aforementioned rotational relationship between the second feed roll and the slip roll is achieved by drive means connected to the first feed roll to impart positive rotation thereto only and to, in turn, impart rotation to the second feed roll solely through its intermeshing relation with the first feed roll and the textile material passing therebetween. However, instead of the slip roll being positively driven by the drive means, as in the first embodiment, there is provided a positive driving connection; preferably in the form of gearing, between the second feed roll and the slip roll for maintaining the aforementioned rotational relationship between the second feed roll and the slip roll. Thus, the flutes of the second feed roll and the slip roll will always have a substantially constant tracking relationship regardless of any variations in the relative rotational angular positions of the feed rolls which may occur due to variations in the density and/or thickness of the textile material passing therebetween during drafting.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of one embodirhent of a drafting system provided with two threeroll control units of the instant invention, and particularly illustrating positively driven bottom fluted feed and slip rolls, but omitting the roll spacing means or collars for purposes of clarity;

FIG. 2 is a vertical sectional view, mostly in elevation, looking rearwardly from a point forwardly of one of the three-roll units, substantially along line 2-2 in FIG. 1',

FIG. 3 is an enlarged fragmentary vertical sectional view taken substantially along line 3-3 in FIG. 2 and particularly illustrating a novel roll spacing means of the instant invention;

FIGS. 4 and 5 are enlarged fragmentary vertical sectional views through the respective first and second or left-hand and right-hand three-roll control units of FIG.

FIG. 6 is an enlarged fragmentary elevation similar to the right-hand portion of FIG. 2, but showing a second embodiment of the invention particularly arranged for utilization of the corresponding three-roll unit as an evener motion.

FIG. 7 is a vertical sectional view taken substantially along line 77 in FIG. 6; and

FIG. 8 is a schematic perspective view similar to FIG. I, but showing a third embodiment of the invention wherein only the bottom feed roll of each three-roll unit is driven positively by the power source, but wherein the second or top feed roll of each three-roll unit, which is driven solely through its intermeshing relation with the corresponding bottom feed roll and the textile material passing therebetween, is geared to the respective slip roll to impart rotation thereto.

DESCRIPTION OF FIRST EMBODIMENT Referring more specifically to the drawings, with particular reference to FIG. 1, the drafting system or drawing frame there shown is particularly arranged for drafting very heavy fibrous textile material. For example, the textile material being directed into the drafting system may be in the form of a plurality of slivers of synthetic, woolen, and/or worsted staple fibers of up to 6 to ID inches staple length or more, with each sliver weighing up to 600 to 800 grains per yard or more. Such slivers may be doubled and drafted into a single composite sliver or web of similar weight to that of each sliver being fed. As is known, the drafting of such heavy, long staple fibers has not been practical heretofore through conventional roll-type drafting systems. Instead, the drafting of such very heavy fibrous textile material has usually been performed on machines equipped with faller bars, such as gill boxes and so called pin drafters, because of the required degree of control of the fibers being drafted, which degree of control could not. to my knowledge, be attained heretofore on conventional roll-type drafting systems.

Although the drafting system of this invention was devised originally for the drafting of very heavy fibers of the character described above, subsequent experiments have shown that three-roll units of this invention are also useful in the drafting of, and contributing to the uniformity of, fibrous textile material of relatively short staple lengths and relatively light weights, such as cotton slivers having the usual staple lengths of about -34 to l V4 inches, as well as synthetic slivers of similar staple lengths and weights, weighing in the range of about 40 to grains per yard.

Three-roll units of this invention may be incorporated in various forms of drafting systems or drafting roll arrangements. Therefore, with the exception of being provided with one or more three-roll control units of this invention, the arrangement of associated rolls of the drafting system may take other forms than that shown in FIG. I, as desired.

As shown, the drafting system of FIG. 1 includes a pair of idler tension rolls l0, 11, a first threeroll control unit 12, a second three-roll control unit I2, and a pair of delivery drafting rolls 13, 14, all of which are serially arranged and which cooperate in drafting fibrous textile material. The textile material may be in he form of a plurality of textile slivers l5 represented by the arrows in FIG. I, which are drafted into a web [5 represented by the arrows forwardly of delivery rolls l3, 14. Web 15' may be rolled up in web form, or it may be condensed into a sliver and directed through calendar rolls 16, through a suitable coiler mechanism 17 and into a sliver can 18 for further processing, as is well known.

The three-roll control units 12, 12' may be of substantially the same or identical construction, and therefore, only the first three-roll control unit 12 will be described in detail and like parts of both three-roll control units will bear the same reference characters. Control unit 12 comprises first and second longitudinally fluted intermeshing feed rolls 20, 21 forming a first nip therebetween and which tightly pinch and feed the textile material I5 therebetween. A longitudinally fluted slip roll 22 is positioned closely adjacent and forms a second nip with the first feed roll 21 and is spaced forwardly from the nip of the first and second feed rolls 20, 2|.

All of the rolls 20, 21, 22 of the particular three-roll unit 12 are of the same circular pitch and the teeth and grooves of the flutes of the rolls of unit 12 are of the same configuration, although these rolls may be of the same or different diameters with respect to each other, as desired. As is well known, circular pitch" means the length of the arc of the pitch circle between the centers or other corresponding points of adjacent teeth of the flutes of a fluted roll. As shown, rolls 20, 21, 22 of unit 12 are all of the same diameter with the axes of rolls 20, 22 spaced about 90 apart with respect to the axis of roll 21. [f substantially greater distance is desired between rolls 20, 22, for example, the second or top feed roll 21 may be of greater diameter than rolls 20, 22.

With respect to first three-roll unit 12, the feed rolls 20, 21 of second three-roll control unit 12' serve as means for pulling the textile material forwardly from the feed rolls of first three-roll unit 12 and forwardly between the second feed roll 21 of unit 12 and the corresponding slip roll 22 while drafting the textile material. Of course, delivery rolls 13, 14 serve as means for pulling the textile material forwardly from the nip of the feed rolls of the second three-roll control unit 12'.

Regardless of whether of not the three-roll control unit 12 serves as an evener, as will be later described with particular reference to FIGS. 6 and 7, the feed rolls 20, 21 are always in intermeshing relationship and one feed roll (the first feed roll in this instance) imparts rotation to the other feed roll solely through their intermeshing relationship and the textile material passing therebetween. On the other hand, the relation ship between the second feed roll 21 and the slip roll 22 must always be such that the flutes of these two rolls are in non-contacting, spaced apart relationship, even though they may be in slight intermeshing relationship, so that they will not tightly pinch or grip the textile material therebetween but, on the contrary, will permit the textile material to slip therebetween while imparting an undulating configuration to the textile material and applying a retardant slip draft thereto as it is being pulled and drafted between the nip of the corresponding first and second feed rolls 21, 22 and the pulling means forwardly of the corresponding threeroll unit.

In other words, a restricting passage of undulating configuration is defined between the proximal rotating, non-contacting, spaced apart, fluted surfaces of second feed roll 21 and slip roll 22, which fluted surfaces rotate at the same speed to avoid scuffing of the textile material, but move at a slower speed than the rate of feed of the textile material into the corresponding drafting zone by the intermeshing fluted feed rolls 20, 21 to thereby obtain improved distribution of the fiber in the textile material to enhance the uniformity thereof. Although the first and second feed rolls are so arranged that the relative positions of the flutes thereof may vary in accordance with variations in the thickness and/or density of the textile material therebetween, the teeth of slip roll 22 are spaced a substantially greater distance from the bottoms of the grooves of the flutes of second fluted feed roll 21 than are the teeth of the first feed roll 20. Also, registration of the teeth of slip roll 22 with respect to the adjacent grooves between the teeth of the second feed roll is maintained within such limits, taking into consideration the radial relationship of the flutes of the two rolls 21, 22, that the textile material will not be tightly pinched between rolls 21, 22.

[n the embodiment of FIGS. 1-3, the drive arrangement is such that positive drive connections are provided between a power source, embodied in a motor 30, and the first feed roll 20 of each three-roll control unit 12, 12', and a positive drive connection is provided between each first feed roll 20 and the corresponding slip roll 22. Such drive arrangement may take the form of a gear train 31 including gears or drive members 32, 33 fixed on corresponding reduced ends of the first feed rolls 20 of the respective three-roll units 12, 12', and a gear 34 fixed on one reduced end of bottom delivery roll 13. Motor 30 is drivingly connected to delivery roll 13. The drive arrangement thus far described constitutes a first drive means for positively driving one of the feed rolls (roll 20 in this embodiment) to, in turn, impart rotation to the other feed roll solely through their intermeshing relationship and the textile material passing therebetween.

it is important to note that, with the exception of the intermeshing relationship of each first fluted feed roll 20 and the respective second feed roll 21 there is no positive drive connection, such as gearing, between the two feed rolls of each control unit 12, 12'. However, in order to ensure that the textile material is not gripped between the flutes of the second feed roll 20 and the slip roll of each unit 12, 12', a second drive means is provided for driving each slip roll 22 in fixed angular relation to one of the feed rolls, but not to both of the feed rolls. In this first embodiment, such second drive means includes a pair of gears 40, 41 fixed on reduced corresponding ends of the respective rolls 20, 22 and meshing with a common intermediate or idler gear 42. Thus, each first feed roll 20 is geared directly to the respective slip roll 22. Since the relationship between each set of gears 40, 41, 42 must not vary during rotation thereof, to the extent that there must be no material back-lash between the rolls 20, 22 of each unit 12, 12', it is preferred that the gears 40, 41, 42 are of the helical or spiral-toothed type.

The reason why back-lash between the gears 40, 41, 42 of each unit 12, 12' should be avoided as much as is practicable is to ensure that there is a minimum of variation in the tracking relationship of the flutes of the respective slip roll and second feed roll, since each successive tooth of slip roll 22 must register with each corresponding groove between the teeth of the adjacent second feed roll at the nip thereof as nearly as possible in alignment with the center of the corresponding groove; i.e., halfway between the adjacent teeth of the flutes of the corresponding second feed roll, during rotation thereof, even though variations in the thickness and density of the textile material passing between the feed rolls 20, 21 will cause slight variations in the tracking relationship of the three rolls of each corresponding unit 12, 12'. Such tracking variations are compensated to some degree during the setting up of each three-roll unit 12, 12', by positioning a length of textile material of optimum weight per unit length between each pair of first and second feed rolls 20, 21. Then, while causing the leading side surface of a tooth of the first feed roll 20 to squeeze or pinch the textile material against the trailing surface of an adjacent tooth of the respective second feed roll 21, taking into consideration the normal direction of rotation of the same, a tooth of the corresponding slip roll 22 is positioned as nearly as is practicable in radial alignment with the center of the groove between two adjacent teeth of the second feed roll 21. Thereupon the gears 40, 41 are tightened on the reduced ends of the corresponding first feed roll 20 and slip roll 22.

ROLL PRESSURE MEANS AND SPACING MEANS Yieldable pressure means is operatively associated with each three-roll control unit 12, 12 and is so arranged that the textile material is subjected to squeezing pressure by the first and second feed rolls 20, 21 to tightly pinch the textile material at the nip thereof, while, at the same time, pressure applied to the second feed roll 21 and the respective slip roll 22 is such as to aid in imparting an undulating configuration to the textile material passing therebetween without tightly pinching the same. Further, spacing or limiting means are provided for limiting the extent of intermeshing of each first feed roll relative to the respective second feed roll 21 while also limiting the extent to which each second feed roll and the respective slip roll may be moved toward one another, there always being a substantially greater distance between the teeth of each slip roll 22 and the bottoms of the grooves of the adjacent second feed roll 21 than is the case with respect to the teeth of each first feed roll 20 relatively to the bottoms of the grooves of the second feed roll 21 at the junctures or nips thereof.

In the preferred arrangement of the apparatus, it is desirable that the outer peripheral surfaces of the teeth of the adjacent second feed roll and slip roll are circularly aligned at the juncture thereof or have a clearance therebetween of up to 0.015 to 0.025 inch, depending upon the density, weight per unit length, type of fibers, and other characteristics of the textile material being drafted. It is to be noted that, although the yieldable pressure means may apply about the same downward force to both bottom rolls 20,22 of unit 12 through top roll 21, the limiting or roll spacing means, to be presently described, ensures that a substantially lesser amount of squeezing pressure is applied to the textile material passing between second feed roll 21 and slip roll 22 than that being applied to the textile material passing between first and second feed rolls 20, 21.

Shown in FIGS. 2 and 3, in association with the first three-roll control unit 12, is a typical weighting system. Similar weighting systems may be used with second three roll control unit 12' and with delivery rolls 13, 14. It is preferred, however, that no weighting system be used with tension rolls 10, 11, and neither of them should be driven by external means, such as motor 30, since their only function is to prevent heavy textile material, when being processed, from opening or disintegrating and piling up against feed rolls 20, 21 of first three-roll control unit 12. The weighting system of FIGS. 2 and 3 cooperates with novel limiting means to obtain the desired displacement between the axes of rolls 20, 21, 22 of unit 12, the illustration and description of such limiting means also being applicable to unit 12.

Opposite ends of the bottom rolls 20, 22 of unit 12 (FIGS. 2 and 3) are journaled in respective pairs of roller neck bearings 45, 46 mounted in bearing blocks 47 adjustably secured to roll stands 49 which are, in turn, suitably secured to the frame of the machine. The limiting or spacing means mentioned heretofore comprises peripherally stepped spacing members or collars 50, 52 suitably secured on proximal enlarged portions of the roller neck bearings 45, 46 for the respective bottom rolls 20, 22. Collars 50, 52 may be secured on the roller neck bearings by a pressed fit.

A peripherally smooth spacing member or collar 51, serving also as a bearing in this instance, is mounted on each reduced outer end of second feed roll 21 and bears against corresponding arcuate concave supporting surfaces of both of the respective stepped collars 50, 52 whenever the unit is not being used as an evener motion; i.e., whenever second feed roll 21 is not to be supported upon the textile material between it and first feed roll 20. Each stepped collar 50, 52 comprises a substantially circular body or block provided with a plurality of said concave supporting surfaces arranged in circularly spaced relationship around the peripheries of the stepped collars 50, 52. In this instance, the body of each stepped collar 50, 52 is provided with five circularly spaced arcuate concave supporting surfaces indicated at 15 (fig. 3), the curvature or radius of each of these surfaces preferably being about the same as the curvature or radius of the corresponding smooth collar 51.

In order to vary the meshing depth of feed roll 20, 21, and to vary the radial relationship between second feed roll 21 and slip roll 22, each arcuate supporting surface 1-5 of each stepped collar 50, 52 is located a different distance from the axis of the respective roll than the other arcuate supporting surfaces on the same collar. Thus, by lifting roll 21 away from the rolls 20, 22, the corresponding roller neck bearings and collars may be rotated to position different arcuate supporting surfaces to be engaged by the peripherally smooth collar 51, thereby readily changing the meshing depth of the feed rolls 20, 21 and also varying the displacement between the axes of rolls 21, 22 when the collar 51 is again positioned in engagement with the collars 50, 52. In practice, it has been found convenient to vary the relative depths of the arcuate supporting surfaces 1-5 of each collar 50 in increments of about 0.020 of an inch, and to vary the depth of the surfaces of steps 1-5 of collar 52 in increments of about 0.005 to 0.010 of an inch. The meshing depth A (FIG. 4) of the feed rolls 20, 21 of three-roll control unit 12 thus may be 0.050, 0.070, 0.090, 0.1 10 or 0.130 of an inch, for example, and the spacing B (FIG. 4) between the outer peripheral surfaces of second feed roll 21 and slip roll 22 may be zero, or 0.005, 0.010, or 0.015 of an inch, or there may be a relatively small intermeshing relationship between the second feed roll 21 and slip roll 22 of, say, 0.010 of an inch, depending upon the size of the flutes of the roll and the nature of the textile material being processed. In all instances, assuming that the two rolls 20, 22 of unit 12 are of the same external diameter, the displacement between the axes of the feed rolls 20, 21 would always be substantially less than the displacement between the axes of second feed roll 21 and slip roll 22. Thus, even though variations in thickness and/or density of the textile material passing between feed rolls 20, 21, and consequent variations in the tracking relationship of feed rolls 20, 21, cause some variations in the tracking relationship between second feed roll 21 and slip roll 22, since slip roll 22 is positively driven by geared connections with first feed roll 20, and is spaced outwardly from second feed roll 21 as compared to the proximity of the teeth of the flutes of first feed roll 20 to the bottoms of the grooves of second feed roll 21, slight variations in the tracking relationship between rolls 21, 22 will not tightly pinch the textile material passing therebetween and will still permit the textile material to slip therebetween while being forced into an undulating configuration. In this regard it is apparent by reference to FIG. 4 that the teeth of the flutes of the rolls 20, 21, 22 are of tapered form and the lands or outer surfaces thereof are quite narrow as compared to the roots or bases of the teeth so that the further out of mesh or the lesser the meshing relationship between the adjacent rolls, the greater the distance any given tooth may move angularly between an adjacent pair of teeth of the adjacent roll without tightly pinching the textile material therebetween.

Any suitable yieldable pressure means may be provided for subjecting the textile material to a heavy squeezing pressure between the feed rolls 20, 21 and to a relatively light squeezing pressure between the second feed roll 21 and the slip roll 22, by maintaining the collar 51 in pressure engagement with corresponding arcuate supporting surfaces of the stepped collars 50, 52 (FIG. 3), at least in the first embodiment of the apparatus As shown in FIGS. 2 and 3, compression springs 60 are provided whose lower ends exert downward pressure against respective foot members 61 engaging reduced outer end portions of the peripherally smooth collars 51. The upper ends of thecompression springs 60 are restrained by suitable bars 62 which normally occupy fixed positions spaced a predetermined distance above the spacing collars 51. Since spring weighting devices as well as dead-weight forms of weighting devices for applying yieldable pressure to drafting rolls are well known in the art, a further description thereof is deemed unnecessary.

METHOD OF OPERATION OF FIRST EMBODlMENT it may be assumed, as a nonlimiting example, that the textile material to be drafted weighs a total of about 2,000 grains/yd. and is in the form of four slivers or ends of 15 denier, 6-inch staple nylon, each end weighing about 500 grains/yd. Desirably, in drafting this type of textile material, tension rolls 10, 11 are used and are spaced rearwardly from the nip of feed rolls 20, 21 of first three-roll control unit 12 a distance less than that of the staple length of the textile material so as to prevent excessive expansion or fluffing of the fibers. Top tension roll 11 rests upon the textile material passing between it and the bottom tension roll 10. Neither of the tension rolls [0, 11 is driven, but they are free to be rotated by the textile material being pulled forwardly therebetween. Although tension rolls 10, 11 are shown as being metallic fluted rolls, either or both of these rolls may be smooth-faced cushion rolls.

Each of the steel fluted rolls 20, 21, 22 of first unit 12 had 13 flutes, each had a diameter of about 2.050 inches, the lands or outer surfaces of the teeth of the flutes thereof each being about 0.100 of an inch wide, and the grooves therebetween each being about 0.298 of an inch deep with a radius of about 0.125 of an inch at the bottom thereof. The meshing depth A of feed rolls 20, 21 of first unit 12 was about 0.070 of an inch, with the paths of the outer peripheral surfaces of second feed roll 21 and slip roll 22 of first unit 12 being spaced a distance 13 (FIG. 4) of about 0.010 of an inch apart from each other.

Similarly, the dimensions A, B of the second unit 12' (H6. 5) were about 0.080 of an inch and about 0.0l5 of an inch respectively, the bottom or first feed roll 20 of second unit 12' being driven at such speed relative to the first feed roll 20 of first unit 12 as to impart a draft of about two to the fibers in the drafting zone defined between the nip of the first and second feed rolls of unit 12 and the nip of first and second feed rolls 20, 21 of unit 12'. The length of such drafting zone was, of course, somewhat greater than the staple length of the textile material.

Although the three rolls of second unit 12' were of about the same external diameter as the three rolls of unit 12, each roll included 19 flutes, the lands of the teeth thereof each being about 0.062 of an inch wide, the grooves between adjacent teeth each being about 0.215 of an inch deep and having a radius at the bottom thereof of abut 0.100 of an inch. The delivery rolls 13, 14 which may be of the fluted type or of the cushioned type, or may include a cushion top roll 14 and fluted bottom roll 13, were driven at such speed relative to the speed of first feed roll 20 of unit 12' as to impart a draft of about 4 thereto in the second drafting zone defined between the nip of feed rolls 20, 21 of unit 12' and the nip of delivery rolls 13, 14, thus imparting a total draft of about eight to the textile material and producing a drafted web or sliver weighing about 250 grains/yd.

As heretofore stated, each pair of feed rolls 20, 21 tightly pinches and advances the textile material therehetween and, although slight variations in tracking relationship between each pair of rolls 21, 22 occur with variation in thickness and/or density of the textile material at the nips of feed roll pairs 20, 21, the textile material is never tightly pinched between the respective pairs of rolls 21, 22. However, the flutes of the slip rolls 22 are positioned in such proximity to the flutes of the respective second feed rolls 21 as to force the textile material passing therebetween into an undulating configuration while thus applying a retardant slip draft to the textile material. To explain further, a retardant force or drag is applied to the textile material between the respective pairs of rolls 21, 22 as the material is, in effect, dragged over the edges of the lands of the teeth of the fluted slip rolls 22 and the corresponding second feed rolls 21, thus tending to redistribute relatively short fibers in the textile material with respect to each other and with respect to the longer staple fibers of the textile material.

With the delivery speed of the drafting apparatus being about 800 to 1,000 feet per minute, tests have shown that the drafted material 15' had a variation in unifonnity (CV) of about 5, such variation having been determined to be within the range of about 4.5 to 6.5.

The 2,000 grains/yd. textile material being fed in the foregoing example represents a typical weight of textile material. It is contemplated that the textile material may weigh up to a total of 6,000 grains/yd. or more and that the draft may be up to a total of 30 or more. Of course, in the drafting of short staple material, for instance, cotton and the like, the average ranges of weights and staple lengths and the average range of draft nonnally produced on conventional drawing frames can be practiced utilizing the three-roll units of the instant invention. Although a drafting system may be equipped with only a single three-roll unit such as that indicated at 12 in FIGS. 1 and 4, it is preferred that at least two such three-roll units be placed in immediate succession in the drafting system as described heretofore, and in some instances, it may be desirable to utilize as many as four such three-roll control units, arranged in series, especially in the processing of very heavy weights of fibers of very long staple of 8 to l2 inches or more.

EVENER MOTION Either three-roll control unit 12, 12 of this invention is readily adaptable to serve as an evener motion when arranged as the rearmost or first set of rolls of a sliver drafting system, the essential requirement then being that the top feed roll 21 of the corresponding unit is permitted to ride upon the textile material so as to increase and decrease the intermeshing relationship between feed rolls 20, 21 and to correspondingly increase and decrease the rate of feed of the textile material in accordance with the movement between feed rolls 20, 21 of relatively thin and thick places, respectively, in the textile material. If the first three-roll control unit is used as an evener motion, for example, the tension rolls 10, 11 would be omitted. In the embodiment of FIGS. 6 and 7, wherein the parts corresponding to those shown in FIGS. 1-5 shall bear the same reference characters, the stepped collar 50 associated with first feed roll is so positioned that a relatively deep arcuate surface 1 thereof is in registration with the top spacing collar 51. The depth of the arcuate supporting surface 1 of stepped collar 50 is such, relative to the diameter of collar 51 thereabove and the depth of the flutes of rolls 20, 21, that surface 1 is spaced from collar 51 during normal operation of the drafting system with the top feed roll 21 resting upon the textile material passing between the feed rolls 20, 21. However, the surface 1 of stepped collar 50 is preferably of such depth that collar 51 will engage the same and prevent bottoming of the flutes of the feed rolls 20, 21 in the absence of any textile material therebetween. When the control unit is used as an evener motion, a circular collar may be substituted for each stepped collar 50, since the top roll 21 will always ride on the stock between it and the bottom feed roll 20.

As shown in FIGS. 6 and 7, since top feed roll 21 moves upwardly and downwardly relative to bottom feed roll 20 in accordance with variations in thickness or density of the textile material passing therebetween, to correspondingly decrease and increase, respectively, the rate of feed of the textile material thereby, it is preferred that means are provided to ensure that the collar 51 on each end of the top feed roll 21 will remain in engagement with the desired arcuate supporting surface of collar 52 and thereby avoid any variation in the radial relationship between the peripheral surfaces of the rolls 21, 22 which would occur in the event that the collar 51 should creep or move about the axis of stepped collar 52 and out of engagement with the desired arcuate supporting surface of collar 52.

Accordingly, a yoke or guide bracket 65 is mounted for angular adjustment relative to each stepped collar 52 associated with slip roll 22. The yoke has a bifurcated upper portion 66 which straddles and slidably engages the reduced outer portion of the corresponding collar 51. To facilitate angular adjustment of slip roll collar 52 relative to the respective yoke 65, a bifurcated lower portion 67 of yoke is loosely penetrated by the reduced medial portion of the corresponding roller neck bearing 46, and one of the legs of the bifurcated lower portion 67 is loosely penetrated by a locking screw 70. The other end of screw 70 is threadedly embedded in the other or opposite leg of the bifurcated portion 67 to clampingly secure the yoke 65 to the roller neck bearing 46 on which the slip roll collar 52 is fixedly mounted. Thus, whenever upward or downward movement of the top or second feed roll 2l occurs, the corresponding bifurcated portion 66 of bracket 65 moves therewith to impart corresponding angular movement to the roller neck bearing 46 and thus to the slip roll spacing collar 52.

In the embodiment of FIGS. 6 and 7, in order to distribute a greater amount of the downward pressure applied to second or top feed roll 21 toward the bottom feed roll 20 than that being applied to the slip roll 22, and thereby to increase the sensitivity of second feed roll 21 to variations in thickness and/or density of the textile material passing between feed rolls 20, 21, a spring loaded plunger adjacent each end of top or second feed roll 21 engages a lever 76 which is pivotally supported above and in a plane rearwardly of the second feed roll 21, as at 77. A bracket 80, suitably secured to roll stand 49, provides the support for lever 76. The lever 76 is provided with a lower cam surface 81, which is so located with respect to the pivot point 77 of lever 76 as to bear against the periphery of collar 51 at a point forwardly of the vertical plane of the axis of second feed roll 21 so that the downward pressure applied to the lever 76 by the spring loaded plunger 75 applies a yieldable downward and rearward force generally toward the first feed roll 21 of substantially greater magnitude than that being applied by the plunger 75 toward the slip roll 22.

MODIFIED DRIVE ARRANGEMENT In FIG. 8 a further modified embodiment of the invention is shown which differs from the first embodiment, and especially with respect to FIG. 1, in that the slip roll 22 of each three-roll control unit is driven by gearing connecting the same with the second feed roll 21 (constituting the second drive means in this embodiment) as opposed to being driven by gearing connecting the same to the first feed roll 20, as is the case with respect to FIG. 1. This modified drive arrangement insures a more precise constant registration or indexing relation of the teeth of the flutes of each slip roll with the grooves between adjacent teeth of the corresponding second feed roll. Since most of the parts shown in FIG. 8 may be identical to those shown in FIG. 1, they shall bear the same reference characters with the small letter a" added thereto to avoid repetitive description.

By comparing FIGS. 1 and 8 it will be observed that the positive drive connections between the first feed rolls 20a of the two three-roll control units 12a, 12a and motor 30a are identical to the driving connections between the rolls 20 of units 12, 12' in FIG. I and the power source or motor 30. However, the gears 40, 41, 42 of FIG. 1 are not used in the embodiment of FIG. 8. Instead, corresponding reduced ends of the second feed roll 21a and slip roll 22a of each unit 12a, 12a have respective gears 91, 92 fixed thereon which are of the same relative diameters as the diameters of the rolls 21a, 22a. These two gears 91, 92 of each unit 120, 120' also are of the helical or spiral type and are arranged in intermeshing relationship with the center line of the tooth of one of the flutes of slip roll 22a positioned, as nearly as is practicable, halfway between the two adjacent teeth of the flutes of the second feed roll 21a at the juncture of rolls 21a, 220. it is apparent that the gears 91, 92 serve to drive each slip roll 22a in fixed angular relation to one of the feed rolls (the second feed roll 21a in this embodiment) and will accurately maintain the predetermined tracking relationship between the corresponding rolls 21a, 22a regardless of the extent of variation in tracking relationship between the first and second feed rolls 20a, 210 as effected by variations in the thickness arid/or density of the textile material passing therebetween.

[n all other respects, the drafting system shown in H6. 8 will operate in the same manner as that described with respect to FIG. 1 and, accordingly, a further description thereof is deemed unnecessary.

Summarizing, it can be seen that (a) by positively driving the first feed roll of each three-roll control unit l2, 12', 12a, 12a (b) by driving the slip roll thereof in fixed tracking or angular relation to either the first or the second feed roll, but not to both of them, by rotating the second feed roll solely through its intermeshing relation with the first feed roll and by the textile material passing therebetween, and (d) by spacing the teeth of the second feed roll further from the roots of the flutes of the slip roll, at the nip thereof, than they are from the roots of the flutes of the first feed roll, at the nip thereof, the feed rolls of each three-roll control unit feed the textile material into and through the corresponding drafting zone as the material thus fed is directed through a restricting passage of undulating configuration defined between the proximal rotating, non-contacting, and spaced apart fluted surfaces of the second feed roll and the slip roll rotating at the same surface speed. The common surface speed of the second feed roll and the slip roll avoids scuffing the textile material, and the passage therebetween imparts an undulating configuration to the textile material as the fluted surfaces of the second feed roll and the slip roll move at a slower speed than the rate of feed of the textile material to thereby obtain improved distribution of the fibers in the textile material being pulled forwardly through the passage and to enhance the uniformity of the textile material being drafted.

In the first embodiment of (FIG. 1), since the gears 40-42 positively interconnect the first feed roll and the slip roll, it is apparent that the gear train 33 may be connected directly to slip roll 22 of each three-roll control unit l2, l2 and arranged to rotate slip rolls 22 in the forward direction, instead of being connected directly to first feed rolls 20, without changing the function of the three-roll control units 12, 12. This is also true with respect to the three-roll units 120, 12a of FIG. 8, although the top rolls 21a then would impart rotation to the respective bottom feed rolls a solely through their intermeshing relationship and the textile material passing therebetween. In either of these latter instances, it should be noted that the relationship of the three rolls of each unit still is preserved in essentially the manner heretofore described with respect to the illustrated embodiments of FIGS. 1 and 8.

In drafting very heavy masses of textile material, it is contemplated that three, four or more of the three-roll control units of this invention may be arranged in series, with or without the first of such units being ar ranged as an evener motion (see FIGS. 6 and 7), as conditions may dictate. [n this way, the amount of draft in each successive drafting zone may be reduced to obtain the ultimate desired draft, the number of slip draft operations will be increased, and the parallelization of the fibers will be further improved.

In the drawings and specification there have been set forth preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim 1. A textile drafting system for drafting staple fiber textile material and comprising at least one three-roll unit including first and second intermeshing fluted feed rolls and a fluted slip roll disposed adjacent said second fluted feed roll and spaced forwardly from the nip of said feed rolls, all the rolls of said unit being of the same circular pitch, means for pulling the textile material forwardly from said feed rolls and between said second feed roll and said slip roll while drafting the textile material, drive means connected to said first feed roll for positively rotating the same to, in turn, impart rotation to said second feed roll solely through its intermeshing relation with said first feed roll and by the textile material passing therebetween whereby the textile material is tightly pinched between and fed toward said slip roll by said feed rolls, transmission means drivingly connecting said second feed roll directly to said slip roll and including means maintaining a fixed rotational relationship between said second feed roll and said slip roll, and the relationship between the flutes of said second feed roll and said slip roll being such as to impart an undulating configuration to the textile material passing therebetween without tightly pinching the same to thereby permit the textile material to slip between said second feed roll and said slip roll and to apply a retardant slip draft to the textile material as it is being pulled and drafted between the nip of said feed rolls and said pulling means.

2. A textile drafting system for drafting staple fiber textile material and comprising at least one three-roll unit including first and second intermeshing fluted feed rolls and a fluted slip roll disposed adjacent said second fluted feed roll and spaced forwardly from the nip of said feed rolls, all the rolls of said unit being of the same circular pitch, means for pulling the textile material forwardly from said feed rolls and between said second feed roll and said slip roll while drafting the textile material, drive means connected to said first feed roll for positively rotating the same to, in turn, impart rotation to said second feed roll solely through its intermeshing relation with said first feed roll and by the textile material passing therebetween whereby the textile material is tightly pinched between and fed toward said slip roll by said feed rolls, transmission means drivingly connecting said first feed roll directly to said slip roll and including means maintaining a fixed rotational relationship between said first feed roll arid said slip roll, means maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll, and the fixed rotational relationship of said first feed roll and said slip roll and the spaced relationship between the axes of said second feed roll and said slip roll being such that, when textile material is being tightly pinched between said feed rolls the relationship between the flutes of said second feed roll and said slip roll is such as to impart an undulating configuration to the textile material passing therebetween without tightly pinching the same to thereby permit the textile material to slip between said second feed roll and said slip roll and to apply a retardant slip draft to the textile material as it is being pulled and drafted between the nip of said feed rolls and said pulling means.

3. An apparatus according to claim 2, including at least one additional three-roll unit comprising a pair of intermeshing feed rolls and a slip roll constructed and arranged in substantially the same manner as, and positioned forwardly of, said first named three-roll unit, and said additional three-roll unit serving as said means for pulling the textile material forwardly from said first named three-roll unit.

4. An apparatus according to claim 3, wherein the feed rolls of said additional three-roll unit are in deeper intermeshing relationship than the feed rolls of said first named three-roll unit.

5. An apparatus according to claim 3, wherein the flutes of said slip roll are spaced further from the flutes of its cooperating feed roll in said additional three-roll unit than in said first named three-roll unit.

6. An apparatus according to claim 2, wherein said means maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll comprises, spacing members freely mounted on the ends of said second feed roll and said slip roll and wherein at least one of the spacing members has a plurality of peripheral surface portions thereon for selective engagement, one at a time, with the other spacing member, and one of said peripheral surface portions being positioned a different distance from the axis of said one spacing member than another of said peripheral surface portions to facilitate obtaining different distances of displacement between the axes of said second feed roll and said slip roll.

7. An apparatus according to claim 2, wherein said means for maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll include yieldable means urging said second feed roll toward said slip roll and into intermeshing relationship with said first feed roll, and spacing means carried by all of said rolls and limiting the extent of intermeshing of said feed rolls and also limiting the proximity of said second feed roll to said slip roll in opposition to said yieldable means.

I I i 

1. A textile drafting system for drafting staple fiber textile material and comprising at least one three-roll unit including first and second intermeshing fluted feeD rolls and a fluted slip roll disposed adjacent said second fluted feed roll and spaced forwardly from the nip of said feed rolls, all the rolls of said unit being of the same circular pitch, means for pulling the textile material forwardly from said feed rolls and between said second feed roll and said slip roll while drafting the textile material, drive means connected to said first feed roll for positively rotating the same to, in turn, impart rotation to said second feed roll solely through its intermeshing relation with said first feed roll and by the textile material passing therebetween whereby the textile material is tightly pinched between and fed toward said slip roll by said feed rolls, transmission means drivingly connecting said second feed roll directly to said slip roll and including means maintaining a fixed rotational relationship between said second feed roll and said slip roll, and the relationship between the flutes of said second feed roll and said slip roll being such as to impart an undulating configuration to the textile material passing therebetween without tightly pinching the same to thereby permit the textile material to slip between said second feed roll and said slip roll and to apply a retardant slip draft to the textile material as it is being pulled and drafted between the nip of said feed rolls and said pulling means.
 2. A textile drafting system for drafting staple fiber textile material and comprising at least one three-roll unit including first and second intermeshing fluted feed rolls and a fluted slip roll disposed adjacent said second fluted feed roll and spaced forwardly from the nip of said feed rolls, all the rolls of said unit being of the same circular pitch, means for pulling the textile material forwardly from said feed rolls and between said second feed roll and said slip roll while drafting the textile material, drive means connected to said first feed roll for positively rotating the same to, in turn, impart rotation to said second feed roll solely through its intermeshing relation with said first feed roll and by the textile material passing therebetween whereby the textile material is tightly pinched between and fed toward said slip roll by said feed rolls, transmission means drivingly connecting said first feed roll directly to said slip roll and including means maintaining a fixed rotational relationship between said first feed roll and said slip roll, means maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll, and the fixed rotational relationship of said first feed roll and said slip roll and the spaced relationship between the axes of said second feed roll and said slip roll being such that, when textile material is being tightly pinched between said feed rolls the relationship between the flutes of said second feed roll and said slip roll is such as to impart an undulating configuration to the textile material passing therebetween without tightly pinching the same to thereby permit the textile material to slip between said second feed roll and said slip roll and to apply a retardant slip draft to the textile material as it is being pulled and drafted between the nip of said feed rolls and said pulling means.
 3. An apparatus according to claim 2, including at least one additional three-roll unit comprising a pair of intermeshing feed rolls and a slip roll constructed and arranged in substantially the same manner as, and positioned forwardly of, said first named three-roll unit, and said additional three-roll unit serving as said means for pulling the textile material forwardly from said first named three-roll unit.
 4. An apparatus according to claim 3, wherein the feed rolls of said additional three-roll unit are in deeper intermeshing relationship than the feed rolls of said first named three-roll unit.
 5. An apparatus according to claim 3, wherein the flutes of said slip roll are spaced further from the flutes of its cooperating feed roll in said additionaL three-roll unit than in said first named three-roll unit.
 6. An apparatus according to claim 2, wherein said means maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll comprises, spacing members freely mounted on the ends of said second feed roll and said slip roll and wherein at least one of the spacing members has a plurality of peripheral surface portions thereon for selective engagement, one at a time, with the other spacing member, and one of said peripheral surface portions being positioned a different distance from the axis of said one spacing member than another of said peripheral surface portions to facilitate obtaining different distances of displacement between the axes of said second feed roll and said slip roll.
 7. An apparatus according to claim 2, wherein said means for maintaining a predetermined spaced relationship between the axes of said second feed roll and said slip roll include yieldable means urging said second feed roll toward said slip roll and into intermeshing relationship with said first feed roll, and spacing means carried by all of said rolls and limiting the extent of intermeshing of said feed rolls and also limiting the proximity of said second feed roll to said slip roll in opposition to said yieldable means. 